System and apparatus for sound reception



'5. PERLMAN SYSTEM AND APPARATUS FOR SOUND RECEPTION Filed Dec. 4, 1940 2 Sheets-Sheet l Til-1 INVENTOR 501. PERL/Vfl/V ATTO R N EYS May 18,- 1943 V I, gum

WITNESS May 18, 1943 s. PERLMAN SYSTEM AND APPARATUS FOR SOUND RECEPTION Filed Dec. 4, 1940 2 Sheets-Sheet 2 INVENTOR 501. PE/PLMfl/V WITNESS ATTORNEYS Patented May 18, 1943 SYSTEM AND APPARATUS FOR SOUND RECEPTION Sol Perlman, Brooklyn N. Y., asslgnor to Hubert J. La Joie, Newark, N. J.

Application December 4, 1940, Serial No. 368,425 Claims. (01179-107) by the person of impaired hearing without the necessity of connecting by a wire or wires the ear translation device necessary to impart the sound intelligence to the ear' of the person, with the microphone and associated mechanisms collecting the various forms of sound intelligence, whether speech or music, which are to be directed to the ear of the listener.

The primary object of the invention is to provide a method and apparatus for the reception of such sound intelligence in which the body of the person using th apparatus is utilized to transmit the sound collected by the microphone, either over the skin surface of the body or through the body, to the ear translation device. Thus, in accordance with my invention, the body of the person using the apparatus is utilized to replace the conventional visible connecting wire or wires now used in this general type of sound transmitting apparatus.

A further object of the invention is to have the body of th person utilizing the apparatus constitute a part of a radio transmitter circuit, modulated by the electrical energy of the speech or tonal frequencies collected by the microphone and to guide the sound intelligence thus collected through the body of the person to suitable auxiliary elements of-the apparatus constituting the ear translation device, where it is converted into sound to which the aural instrumentalities or organs of the person are responsive. i

A further object of the invention is to provide a method and apparatus by means of which electrical currents into which the sound or tonal frequencies impinging upon the microphone are translated may be carried over the surfaces of the body or through the body to the ear translation device.

Other objects and advantages of the invention will become apparent to those skilled in the art from a, description of a particular embodiment of an apparatus utilizing the invention, but it is to be understood that the particular example illustrated inthe drawings and hereinafter to be described is by way of demonstration of the manner oi?- utilization of my novel concepts rather than by way of limitation.

In -its broadest aspects, my novel apparatus comprises a microphone and auxiliary elements, including an audio modulator, a radio frequency generator, and a sound modulated radio frequency amplifier, all or which are adapted to be enclosed in a portable casing to be carried by the person using th apparatus and suitably supported 0n the body. The apparatus constructed in accordance with my invention, includes also a speech amplifier and an ear translation device having suitable auxiliary elements capable of picking up the electrically translated sound intelligence as conducted through the body and amplified or reinforced to a normal or supernormal level for reception by the ear of the listener. An important feature of my novel apparatus is theprovision of two body electrodes, in contact with or capacitively coupled to, the body of the person using the apparatus, one at the. point of transmission and the other at the point of reception, the first body electrode serving as a contact medium for the electrical energy between the transmitter and the body, and the other electrode being effective to collect the electrical energy transmitted through or over the surface of the body by the transmitting apparatus.

In the drawings, in which a specific embodiment of my'invention is illustrated, Fig. 1 is a diagrammatic lay-out of the various elements of the transmitting apparatus and the manner of their interconnection including the transmitter body electrode; Fig. 2 is an electric wiring diagram of the receiving circuit, the rectifier of the radio frequency energy upon which the electrical energy of the sound frequencies are superposed, the ear translation device, and the body electrode collecting the electrical energy transmitted through or over th surface of the body by the transmitting apparatus; Fig. 3 is a schematic diagram showing the elements of the transmitting apparatus, the elements of the receiving apparatus, including the resonant responsive circuit, the rectifier, and the ear phone, and the two body electrodes, and showing the energy conductive paths through the body; Fig. 4 shows, by way of illustration, the elements of my novel apparatus in position upon the body of the user; and Fig. 5 is a sectional view through the receiving apparatus, in position within, and upon, the ear of the user. a

Referring now more particularly to Fig. 1, constituting an electrical wiring diagram of the transmitter circuit, 1 designates the conventional type of microphone used for collecting the sound intelligence which is to be transmitted in accordance with my invention to the ear of the listener, The function of the microphone is to collect such sound intelligence and convert it into an electrical potential. It will be understood by those skilled in the art that this electrical potential varies according to the frequency of the sound vibrations impinging upon the microphone. The varying electrical potentials into which the sound intelligence has thus been converted by the microphone are applied to a resistor 2, connected across the two terminals of the microphone and to the grid terminal of a vacuum tube 3. The vacuum tube 3 is effective to' amplify the varying electrical potentials produced by the particular sound frequencies in the speech amplifier circuit, the amplification being further enhanced by a vacuum tube 4 and still further by a vacuum tube .5 in a manner well known in the art. The vacuum tube 5 is an audio modulator tube. The radio frequency energy is generated by the elements constituted by the vacuum tube 8, and by the vacuum tube I interposed in the circuit after the-vacuum tube 8, and effective to amplify the radio frequency energy. Associated with the vacuum tube I, being disposed between such tube and the amplifier tube 5, is a modulator auto-transformer 6 common to the anode circuits of the vacuum tubes 5 and I. The radio frequency energy which has been amplified by the vacuum tube 1 is fed into a tank circuit 9 constituted of suitable inductance and capacitance elements. The modulation of the radio frequency energy in tank circuit 9 is accomplished in a manner well known in the art. In accordance with my invention, however, the modulated radio frequency energy of the tank circuit 9 is conveyed to an electrode I conductively or capacitively coupled to the body of the person utilizing the apparatus, in proximity to the casing carrying the transmitting apparatus. This coupling of the electrode I0, carrying the modulated radio frequency energy received from the tank circuit 9, causes the body .of the person to become a load on the tank circuit 9, the body absorbing the modulated generated radio frequency energy supplied to the body by the electrode III by such tank circuit.

The details of the transmitter circuit and elements just described, except for the body electrode, constitute no part of my invention and therefore are not specifically described or identifled except that the conventional battery II and controlling switch I2 are interposed in the circuit. The entire transmitter circuit and pertinent elements may be housed within a casing suitably supported upon the body or the clothing of the person using my novel apparatus, the

body electrode being conductively or capacitively coupled to the body and connected to the transmitter circuit by the single wire I3.

Referring now more particularly to Fig. 2, a second body electrode I4, positioned in proximity to the ear of the user, is either conductively or capacitively coupled to the body, to absorb the modulated radio frequency generated electrical energy that is transmitted from the electrode III by the body. This absorbed modulated radio frequency generated electrical energy is conveyed from the electrode I4 to a tank circuit I which is resonantly responsive to such energy. Dependent upon the choice of suitable values of inductance and capacitance in such tank circuit I5, there will be absorbed, by such circuit, the maximum available amount of modulated radio frequency generated electrical energy from the body of the user, the absorption taking place through the body electrode I4. From the resonant responsive circuit I5, the energy is transmitted through a rectifier I6, effective to separate the electrical energy of sound modulation from the carrier of the energy flowing in tank circuit I5, to the ear translation device II. The separation is due, as will be recognized by those skilled in the art, to the asymmetrical response of the rectifier I6 to the flow of radio frequency energy through it.

The ear translation device II, which may be in the form of a conventional ear-phone, converts the electrical energy of the sound modulation of the radio frequency generated carrier into sound of sufficient magnitude to be audible by the person using the apparatus.

Referring now to Fig. 3, there is illustrated therein schematically the transmitter circuit and component parts thereof, and the receiving circuit and component parts thereof. To the modulated power amplifier of the transmitter circuit is connected the body electrode II) as hereinabove described, and to the resonant responsive circuit of the receiving circuit is connected the body electrode I4; In the schematic diagram, represented by Fig. 3, I have illustrated three current paths constituting the paths which the electrical energy utilized and transmitted by the different elements of my apparatus is assumed to take by the resistance and capacitance of the body constituting the transmitting medium for such energy. It is my theory, to which, however, I do not wish to be restricted, that the body of a person utilizing my apparatus behaves as an imperfect dielectric, that is, the body exhibits the characteristics of a dielectric with a low leakage resistance, so that it conveys the radio frequency generated electrical energy from one body electrode to the other through the conductive and capacitive characteristics of the body.

In Fig. 3, therefore, I illustrate in dotted lines the three paths that the electrical energy takes through the body. One of the paths, I8, constitutes the resistance and capacitance shunted across the output tank circuit 9, which load such tank circuit, the load being thus produced by thegbody. The transmission path I8, constituted of a resistance and capacitance, is that between the two body electrodes IIl'and I4. The transmission paths I8 and I9 through the body, having a definite resistance and capacitance, re-

. quire a readjustment of the tank capacitance of the tank circuit 9 in order to maintain such tank circuit 9 in a resonant condition when the body electrode I 0 is suitably placed upon the body.

Similarly and effective in the same manner as the path l8,the resistance and capacitance,identifled generally as the path 20, are shunted across the second body electrode I4 and the resonantly responsive circuit I5. This resistance and capacitance are effective to load such tank circuit.

I When the body electrode I4 is suitably placed upon the body of the person using the apparatus, the effect of the path 20, conjointly with the path I9, is to require a readjustment of the tank capacitance of the resonantly responsive tank circuit I5 to maintain such tank circuit in the proper resonant condition with respect to the position of the body electrode I 4.

As a result of experimental work, it has been found that the radio frequency generated energy is conveyed to the resonantly responsive tank of the receiver circuit more efliciently by transmission over the surface of, or through, the body than if the transmission 01' the energy were effected through suitable antenna devices. By reason oi this greater efllciency, the desirability of my novel method of conveying sound intelligence ex- 1 hibits not only the advantage of dispensing with the use of wire or wires whlch,visibly connect the microphone with the ear translation device, but a better transmission, without such wires, is actually eiiected than could be produced by means of such wires.

In Fig. 4 I have shown, by way of illustration, the elements oi my novelapparatus in a convenient form to be carried upon the person. In such figure, the box 2| containing the transmitting apparatus, including the microphone, may be conveniently suspended upon the chest of the wearer by means of tapes or straps 22, 22. The source of current for the apparatus, for instance, acompact battery 23, may be conveniently carried in a vest pocket. To the-transmitting apparatus is connected the body electrode I0, placed in juxtaposition with the skin of the body of the wearer at any convenient place.

The receiving apparatus, generally designated at 24, is held in position within and upon the ear of the user in the conventional manner of earphones utilized by persoris of impaired hearing.

In Fig. 5 I have illustrated the general outline of the inner and outer ear of a human being within and upon which my novel receiving apparatus may be positioned. Referring more particularly to such figure, the device comprises a casing 25, which houses the condenser and rectifier units of the receiving apparatus, the casing being supported in juxtaposition with an ear mold generally designated as 26. The ear-phone I1 is snapped into the ear mold 26, the mold serving as a support for such ear-phone and associated parts.

Wound upon the periphery'of the ear-phone IT is a coil 21, which, with the associated condenser in the ear-phone case 25, is resonant to the transmitter. The body electrode equivalent to the body electrode l4, schematically illustrated in Figs. 2 and 3, is constituted of a wire 28, conveniently formed in the shape of a hook to be placed over the ear. A fiat, thin strip of metal 29 constitutes the contact member for the body electrode 28, which fiat, thin strip of metal is in direct contact with a second fiat, thin strip of metal 30, partially surrounding the ear mold 26, and in contact with the interior skin surface of the car. It will be understood by those skilled in the art that when the ear-phone I1 is snapped into place within the mold, the two fiat thin metal strips 29 and 36 are in contact. The ear mold 26 has a centralpassage or channel 3i through which sound may be transmitted from the ear-phone I! to the appropriate opening in the ear extending to the aural responsive organs within the ear.

While I have described, with reference to Fig. 5, a specific construction of ear-phone supporting structure and contacting elements, it is obvious that other forms of ear-phone supporting and contacting units may be utilized in carrying out the objects and securing the advantages of my invention.

While I have described a specific embodiment of my invention, it is obvious that various changes therein, particularly in the arrangement of the several elements and combination of circuits, may be made without departing from the invention.

I claim:

1. An apparatus for the transmission to, and reception of sound intelligence by a person of impaired hearing, which comprises a transmitter circuit adapted to be carried by the person using the apparatus and including means for conversion of sound intelligence into electrical 'cncrgy, means for amplifying the varying electrical potentials thus produced, and a body electrode for disposition in contact with the body of the person using the apparatus and adapted to transmit the electrical energy from such circuit to the users body, and a receiver circuit carried by the user and including a second body electrode, a resonant responsive circuit connected to said body elec trode and an ear translation device connected to said resonant responsive circuit, said second body electrode being coupled to the body of the person at a point spaced from said first electrode and adapted to absorb the electrical energy transmitted through the body of the person from said first body electrode, whereby said sound conversion means and said ear translation device are solely connected to one another by the body of the user.

2. An apparatus for the transmission to, and reception of sound intelligence by, a person'oi impaired hearing, which comprises a transmitter v circuit adapted to be carried by the person using the apparatus and including a microphone for conversion of sound intelligence into electrical energy. means for amplifying the varying electrical potentials thus produced, a tank circuit, and a body electrode for disposition in contact with the body of the person using the apparatus and adapted to transmit the electrical energy from such circuit to the users body, and a receiver circuit carried by the user and including a second body electrode, a resonant responsive circuit connected to said body electrode, a rectifier connected to said resonant responsive circuit and an ear translation device connected to said rectifier, said second body electrode being coupled to the body of the person at a point spaced from said first electrode and adapted to absorb the electrical energy transmitted through the users body from said first body electrode, whereby said microphone and said ear translation device are solely connected to one another by the body of the user.

3. An apparatus for the transmission to, and reception of sound intelligence by a person of impaired hearing, which comprises a transmitter circuit adapted to be carried by the" person using the apparatus and including a microphone for conversion of sound intelligence into electrical energy,-a speech amplifier, an audio modulator, a modulated power amplifier, a radio frequency generator, and a body electrode for disposition in contact with the body of the'person using the apparatus and adapted to transmit the electrical energy from such circuit to the user's body, and a receiver circuit carried by the user and including a second body electrode, a resonant responsive circuit connected to said body electrode, a rectifier connected to said resonant responsive circuit and an ear translation device connectedv to said rectifier, said second body electrode being coupled to the body of the person at a point spaced from said first electrode and adapted to absorb the electrical energy transmitted through the usersbody from said first body electrode, whereby said microphone and said ear translation device are solely connected to one another by the body of the user. I

4. An apparatus for the transmission to, and reception of sound intelligence by, a person of impaired hearing, which comprises a transmitter circuit adapted to be carried by the person using the apparatus and including means for conversion of sound intelligence into electrical energy, a body electrode for disposition in contact with the body of the person using the apparatus and adapted to transmit the electrical energy from such circuit to the users body, a receiver circuit carried by the user and including a second body electrode, a resonant responsive circuit connected to said body electrode and an ear translation device connected to said resonant responsive circuit, said second body electrode being coupled to the body of the person at a point spaced from said first electrode and adapted to absorb the electrical energy transmitted through the body of the person by said first electrode, whereby said transmitter circuit and the ear translation device are solely connected by the users body.

5. An apparatus for the transmission to, and reception of sound intelligence by, a'persori of impaired hearing, which comprises a transmitter circuit adapted to be carried by the person using the apparatus and including means for conversion of sound intelligence into electrical energy, a body electrode for disposition-in contact with the body of the person using the apparatus, said electrode being connected to said transmitter circuit and adapted to transmit the electrical energy from such circuit to the users body, a receiver circuit carried by the user and including a second body electrode and means for translating the electrical energy transmitted to said second body electrode into sound intelligence, said second body electrode being coupled to the body of the person at a point spaced from said firstelectrode and adapted to absorb the electrical energy transmitted through the body of the person by said first electrode, whereby the two body electrodes are solely connected by the user's body.

6. An apparatus for the transmission to, and reception of sound. intelligence by, a person of impaired hearing, which comprises a transmitter circuit adapted to be carried by the person using the apparatus and including a microphone for conversion of sound intelligence into electrical energy, means for amplifying the varying electrical potentials thus produced, and a body electrode disposed in contact with the body of the person using the apparatus and adapted to transmit the electrical energy from such circuit to the users body, and a receiver circuit carried by the user and including a second body electrode, a resonant responsive circuit connected to said second body electrode, a rectifier connected to said resonant responsive circuit and an ear translation device connected to said rectifier, said second body electrode being coupled to the body of the person at a point spaced from said I first electrode and adapted to absorb the electrical energy transmitted through the users body from said first body electrode, whereby said microphone and said ear translation device are solely connected to one another by the body of the user.

7. In the method of transmitting to, and receiving sound intelligence by, a person of impaired hearing, the step which comprises utilizing the conductivity of the human body to convey sound intelligence translated at one portion oi the body to electrical energy to another portion of the body where it is reconverted into sound intelligence, the point on the body at which the electrical energy is received for reconversion being spaced from the transmitting point on the body and the transmission to such-point of the as the only means for conducting electrical energy between the transmitting and receiving points.

8. In the method of transmitting to, and receiving sound intelligence by, a person of impaired hearing, the steps which comprise converting the sound intelligence directed to the person into electrical energy at one portion of. the body of such person, conducting the varying electrical energies to which the sound intelligence has thus been converted through the body of the person to another portion thereof at a point spaced from the point at which such energy was transmitted to the body and in proximity to the ear of the person, reconverting the electrical energy at such point into soundintelligence, and transmitting such sound intelligence to the aural responsive organs of the ear, the transmission oi. the electrical currents from the transmitting point on the body to the receiving point on the body at the place spaced from such transmitting point being effected solely through the body of the person, said steps being carried out with the body as the only means for conducting electrical energy between the transmitting and receiving points.

9. In the method of transmitting to, and receiving sound intelligence by, a person of impaired hearing, the steps which comprise converting the sound intelligence directed to the person into electrical energy at one portion of the body of such person, amplifying the varying electrical potentials thus produced, utilizing the conductivity of the human body to transmit the varying electrical energies to which the sound intelligence has thus been converted to a point on the body in proximity to the ear of the person, reconverting the electrical energy into sound intelligence and transmitting such sound intelligence to the aural responsive organs of the ear, the transmission of the electrical energy being effected from a point on the person's body spaced from the point on the person's body in proximity to the ear of the person, solely through the body of the person, and said steps being carried out with the body as the only means for conducting electrical energy between the transmitting and receiving points.

10. The method of transmitting to, and receiving sound intelligence by, a person of impaired hearing, which comprises converting the sound intelligence directed to the person into electrical energy, amplifying the varying electrical energy thus produced, conducting the energy to an electrode in contact with the body of the person, utilizing the conductivity of the, human body to transmit the varying electrical energies to which the sound intelligence has thus been converted, to an electrode positioned at a point spaced from the point of contact of the first electrode and in contact with the ear of the person, reconverting the electrical energy thus produced into sound intelligence, and transmitting such sound intelligence to the aural responsive organs of the ear, the transmission of the electrical energies from the spaced points of contact of the two electrodes being efiectedsolely through the body of the person, and said steps being carried out with the body as the only means for conducting electrical energy between the transmitting and receiving points.

s01. PERLMAN. 

